Rebound retarder



Sept 5 1927 J. B. KIRBY REBOUND RETARDER Filed Feb. 25, 1924 Sheets-Sheet l E. PQM).

Sept. 6,1927, J B KIRBY 1,641,334

` REBOUND i RET'ARDER Fi1edFeb-f25, 1924 2 sheets-sheet 2 l Jm E Irwemior Patented sept. s, ist?.

` UNITED STATES PAT 1,641,334 ENT roFFlcE.

JAMES B. KIRBY, OF WST RICEFIELD, OHIO.

-BEBoUivn RETARDER.

Application 'led February 25, 1924. Serial No. 694,898.

This invention relates to that class of devices, popularly' known as shock absorbers employed for restraining the excessively v10- -lent movement of automobile springs thereby rendering the movements of the vehicle body more comfortable and decreasing the danger of breaking the springs. The objects of the invention are the provision of a.

new, compact, simple, and easily manufac-i.

tured device of this character, which shall consist of the smallest possible number oi parts, be readily applied to the vehicle, adjust itself automatically to varying loads, and exert a restraining action at all times proportionately to the force impressed '.,thereong While further vobjects and advantages of the invention will become apparent as the description proceeds.

In the drawings accompanying' and form ing a part of thisapplication I have shown certain physical-structures in which my inventive ideas may be employed although it .will .be understood that these drawings are intended merely to bev illustrative of the principles of my invention and not exhaustive of the structures by which the sam'e can. l

'l be utilized. Fig. 1 illustrates a part of an automobile frame and spring equipped with one form of my invention Fig. 2 is a secview corresponding tothe line 6-'6 of Fig.

7 Fig. 7 isa sectional view corresponding to the line 7 7 of Fig. 6; and Fig. 8 is a sectional view of another'moditication.

Describing the parts by reference char-I acters, 1 represents a part ofthe frame of an automobile, 2 one of the springs, an'd 3 one of the axles to which the spring is fastened by suitable U-bolts 1-4. Firstdescribing particularly the formof my invention shown in Figs. 1, 2, and 3, 5 represents a cy lindrical metallic casing having at one side a bracket 19 by which it can be attached to the frame, its interior 'portion being formed throughout the greater partV of its length .with coarse threads 6--6 of steep pitch with which cooperates a longitudinally movable f plunger 7 threaded to engage the same. The

ends ofthe casing are closed by suitable heads 8 and 9, threadedor otherwise suitably secured thereto. One of these heads, as 8, is formed with a suitable stuffing box 10 traversed by the rock shaft 11, one end'of which is received in the socket 12 of the ,head 9. -Rigidly secured to theouter end of this shaft is the lever 13 formed at its end with a ball 14 received in the socket l5 carried by the vertical rod 16, the opposite end of which is suitably articulated to fthe axle 3. Any suitable or convenient expedient may 4be employed for preventing the arm from turning on the shaft, for example the end' of the shaft may be iiuted as shownfat 17 and the arm driven or-clamped thereon.

Between the heads 8 and 9'the exterior'of this shaft is formed with longitudinal ribs` 18, the. plunger 7 being formedwith a centralA aperture conforming closely `to this shaft and its ribs. The pitch of the thread is so adjustedrelatively to the length of the casing .and thickness of the plunger as to cause the latter to traverse substantially the full length thereof in a 90o movement of the arm 13. y A

The end portions of the chambers'are connected .together by a system of passageways which may conveniently take the formof a pair of radial bores 20-20 intersecting a.

longitudinal bore 21. The outer ends' 0f the bores` 20-2O are then closed permanently by plugs 22-22 while the outer end of the bore 21l is provided with a threaded socket 23 terminating lin a' seat 24 and receiving theadjustablescrew 25 constituting an'adjusting valve. A lock nut 26 can be employed for preventing accidental movement.

In use the casing isfilled with glycerine, lubricating oil, o'r other non-freezing liquid.

Owing to the fact that the casinglshaft,

plunger, etc. can be-made by broaching and other quantity 'production' processes .it is possible to manufacture a device of this sortat a minimum of expense, 4while the parts being few in number and rugged in construction are readily made and assembled and not readily broken.

In the device shown in Figs. 4 to7 Yinelusive 5a represents a cylindrical casing formed'interiorly withl a plunger 7'3L and its ends with heads 81 and '9 as before. The head'8a is formed with a stuffing boxV "10H through .which passes the shaft 11l whose opposite end isset Ain the'socket 12 of the opposite, head. In this embodiment, how.- ever, the projecting end oftheI shaft is mounted in the arm 30 of the bracket 31 carried by; the frame 1, leaving the `casing rotatable upon said shaft. Inside the-casing this shaft as before is formed with the longitudinal ribs 18a closely embraced by the plunger 7s.. Secured to the exterior of the casing by any suitable means such 'as screws 32-32 is the flexible strap 33 which `after wrapping itself va suiiicient distance `around thecasmg is attached to theaxle- 3 in any suitable manner, for example by means of the bracket 34r attached thereto by the clarnp. By the operation of the strap Y the casing will b e turned Iin one direction moving the plunger along the casing in an obvious manner.y ITo restore the casing to' its former position I have shown a volute spring 36.v having lone end fastened relatively to the casing (as by ,attachment to' a lug formed in the adjacent head as shown u at1 37)'. and the other end fastened to the lunger as at 438.'l This spring can' operate lothloy lits longitudinal expansion and by its torsion.. WVhen it isl attached to the head 91as shown herein, thelatter is preferably 'secured tothe casing by screw threads as. herein illustrated, the direction oftwist of the spring A36 is so chosen that the same will heawound up as the head is screwed into place. f Of course I do not limit myself to -these features. This' spring is also arranged" to-oppose the pull .ofthe strap 33. The

pitch of thethreads ais preferably much less'abrupt thanin the case first' described,' since a larger angular vmovement may `be,- L employed;

In `this embodiment ,I have shown adevice requiring .1l/2 revolutions of the casing to move the plunger from one end to the other. To oppose this movement,

the'casng is filled with. suitable liquid as before, and a controllable duct provided at some convenient place for regulating the flow of vthis liquid from Ione side to the 4' erallythrough ducts 20 at each end of thev chamber. The outer end of the bore 21il is lenlarged for the reception of the adjusting screw 25a which is hereshown-as provided with a long shank 40 terminating in a ta-` pered extension 40a. In order to permit return ofl the`casing under the comparatively small forcejof the spring 36 I preferably form the plunger with a suitabley relief valve adapted'to open easily by pressure in 'the appropriate direction. This valve may comprise a headed Amember 41 seated at one ,side of the plunger and having it shank 42 embraced by al weak spring 43 received iny a recess 44 `on the opposite face of the plunger.v l u u In thedevice shown in Fig.' 8 the casing 5" is formed with a' smooth cylindrical Wall,

unbroken except for one or more longitudinal keyways 45, and the shaft 11b is made with an enlargement inside the casing upon I which'the multiple pitch thread Gb is formed.

The plunger 7b is` threaded to match the lshaft and slotted to match the casing, a key or spline l46 being used to prevent rotation lof the plunger. In this case I have shown the casing with one head 9b integral and the other, '8F bolted., The increased thrust 'caused by threading vthe shaft is-cvarried by suitable bearings 47. This ydevi'cecan bez afiixed to the vehicle parts in either of the modes heretofore described and the liquid transfer accomplished either as heretofore suggested vor by having 'the' plunger so loosely adjusted that natura leakage will suflice.

Any of thesedevices will adopt a position in its 'casing depending'upon the normal deflection of the vehicle springs. When a valve is used it is so adjusted that the liquid will pass from 'one side'of the plunger'to `the other with sufficient readiness to avoid transmitting' to the frame the minor vibrations of the axle while preventing `any severe throw of the body consequent on a major deflection of the spring. It will be understood, however, that other kinds of valves can be used orthat a passageway o f fixed size is Ipossible, the valve4 being omitted. This is lthe condition vexisting 4in the device shown wheneverl the valve isl whollyopen.A Likewise it is feasible to make and use thev device Withoutany passageway,

ion

theplun'ger being made so loose that the leakage therepast affords the approximate retardationrequired. This is the condition actually existing in the devices vshown in Figs. 1 to 7 inclusive whenever the valve is wholly closed.

I do mot limit myself tothe use of integral ribs on the shaft, since they can beA scope ofmy invention and within the prior Vart and annexed claims.

Having thus described my invention what I claim is: I

1. In a device of the character described,

' a hollow internallythreaded, liquid containing casing having liquid--tightl heads, a shaft journ'aled axially within said casing, a plunger threaded in saidca'sing and apertured for said shaft, theshaft and plunger having interiitting provisions lwhereby rel ative sliding is permitted and 'screwing of 'the plunger along thecasing is compelled,

means for attaching said casing and shaft, the one to the body and the other to an axle of a vehicle, said means including a strap spring and to restrict'sai aeaiee whereby relative movement between 'said casing and shaft is caused in one direction. means including a spring for causing relative movement of said casing and shaft in the opposite direction, and a one wayvalveadapted' automatically to establish free com: munication between the ends of said casing while said plunger is bein communication at other times.

2. In a device of the characterdescribed, an internally threaded, liquid containing casing having liquid-tight heads, a shaft journaled laxially within said casing, a plunger threaded in said casing and apertured for said shaft, the shaft and plunger havin'o inter-fitting provisions whereby relative sliding is 'permitted and screwing of the plunger along the casing is compelled, a flexible vtension member adapted to be wound around said casing, means for attaching said shaft and member to two independently movable parts, a spring operatively connected between said vshaft and casing and arranged to opposerelative movement of the parts by said tension member, and means for permitting the movement of liquid from one end of said casiiig'to the vother at different rates depending upon the direction of its flow.

' 3. In a device of the character described, a hollow, cylindrical, liquid-containing casing having heads and internal threads, a

moved by saidl said a hollow, cylindrical, liquid-containing casof said casing, a' plunger in said casing connected to said shaft so as to slide therealong' but not to turn relatively thereto, said plunger having threads engaging said first threads, means for securing said' shaft and casing, the one to the body and the other to the axle of a vehicle, one of said means ebmprising a iiexible strap, a spring insaid casing'operatively engaging said plunger to keep said strap taut-,there being a passa eway between the ends of sa1d caslng, an a check-valve in said passageway adapted te* open in a direction to permit movement of said plunger by said spring.

In testimony whereof, I hereunto aiix my signature.

JAMES B. KIRBY. 

